2018 QUARTER 03

DM-06 - Grid representations
  • Explain how grid representations embody the field-based view
  • Differentiate among a lattice, a tessellation, and a grid
  • Explain how terrain elevation can be represented by a regular tessellation and by an irregular tessellation
  • Identify the national framework datasets based on a grid model
DC-19 - Ground verification and accuracy assessment
  • Evaluate the thematic accuracy of a given soils map
  • Explain how U.S. Geological Survey scientists and contractors assess the accuracy of the National Land Cover Dataset
DM-11 - Hierarchical data models
  • Illustrate the quadtree model
  • Describe the advantages and disadvantages of the quadtree model for geographic database representation and modeling
  • Describe alternatives to quadtrees for representing hierarchical tessellations (e.g., hextrees, rtrees, pyramids)
  • Explain how quadtrees and other hierarchical tessellations can be used to index large volumes of raster or vector data
  • Implement a format for encoding quadtrees in a data file
CP-03 - High performance computing
  • Describe how the power increase in desktop computing has expanded the analytic methods that can be used for GIS&T
  • Exemplify how the power increase in desktop computing has expanded the analytic methods that can be used for GIS&T
DM-42 - History of understanding Earth's shape
  • Describe how scientists’ understanding of the Earth’s shape has evolved throughout history
  • Describe the contributions of key individuals (e.g., Eratosthenes, Newton, Picard, Bouguer, LaPlace, La Candamine) to scientists’ understanding of the Earth’s shape
  • Explain how technological and mathematical advances have led to more sophisticated knowledge about the Earth’s shape
  • Describe and critique early efforts to measure the Earth’s size and shape
DM-52 - Horizontal datums
  • Discuss appropriate applications of the various datum transformation options
  • Explain the difference between NAD 27 and NAD 83 in terms of ellipsoid parameters
  • Outline the historical development of horizontal datums
  • Explain the difference in coordinate specifications for the same position when referenced to NAD 27 and NAD 83
  • Explain the rationale for updating NAD 27 to NAD 83
  • Explain why all GPS data are originally referenced to the WGS 84 datum
  • Identify which datum transformation options are available and unavailable in a GIS software package
  • Define “horizontal datum” in terms of the relationship between a coordinate system and an approximation of the Earth’s surface
  • Describe the limitations of a Molodenski transformation and in what circumstances a higher parameter transformation such as Helmert may be appropriate
  • Determine the impact of a datum transformation from NAD 27 to NAD 83 for a given location using a conversion routine maintained by the U.S. National Geodetic Survey
  • Explain the methodology employed by the U.S. National Geodetic Survey to transform control points from NAD 27 to NAD 83
  • Perform a Molodenski transformation manually
  • Use GIS software to perform a datum transformation
AM-56 - Impacts of transformations
  • Compare and contrast the impacts of different conversion approaches, including the effect on spatial components
  • Create a flowchart showing the sequence of transformations on a data set (e.g., geometric and radiometric correction and mosaicking of remotely sensed data)
  • Prioritize a set of algorithms designed to perform transformations based on the need to maintain data integrity (e.g., converting a digital elevation model into a TIN)
KE-12 - Implementation planning
  • Discuss the importance of planning for implementation as opposed to “winging it”
  • Discuss pros and cons of different implementation strategies (e.g., spiral development versus waterfall development) given the needs of a particular system
  • Create a budget for the resources needed to implement the system
  • Create a schedule for the implementation of a geospatial system based on a complete design
PD-05 - Implementation tasks
  • Explain the rationale for piloting and prototyping new systems
  • Plan a formal quality assurance procedure
  • Construct an effective database structure in a selected GIS or database software based on the physical model
  • Acquire data from primary and secondary sources
  • Transfer data from primary and secondary sources into the database
  • Create customized programs and scripts based on an application design
GS-22 - Implications of distributed GIS&T
  • Describe the advantages and disadvantages to an organization in using GIS portal information from other organizations
  • Describe how inter-organization GIS portals may impact or influence issues related to social equity, privacy and data access
  • Discuss how distributed GIS&T may affect the nature of organizations and relationships among institutions
  • Suggest the possible societal and ethical implications of distributed GIS&T